This proposal is for purchase of an advanced ultrasonic imaging system to support the needs of multiple current NIH funded investigators in the Section of Cardiovascular Medicine, and Image Processing and Analysis Group of the Department of Diagnostic Radiology. Each of the investigators is conducting research that depends on or would benefit from the ability to evaluate cardiac function, mechanics and/or morphology from ultrasound imaging, and none could afford independently the purchase of the necessary ultrasonic imaging equipment. A key project (Project 1) focuses on the development of image analysis tools, which could be utilized for calculation of regional cardiac- and fiber specific strains in the heart from high-resolution 3D images for accurate determination of myocardial viability. The project will include validation of a 3D echocardiographic approach, using complex arrays of sonomicrometers in experimental models of infarction, and pilot clinical studies. These image analysis tools would be applicable to several of the other ongoing projects. Improved ultrasound transducer technology has allowed generation of cine 3D ultrasound images of the heart in large animals and analysis of regional and global left ventricular (LV) function in small animal models including transgenic mice. The collaborating investigators employ a variety of experimental small and large animal models. The proposed ultrasonic imaging system meets all of the needs of the investigators. The proposed equipment will be utilized in four NIH supported R01 projects and two K08 awards. Two of the projects (Project 1 & 2) require 3D rendering of the LV in canine models of ischemic injury. The proposed analyses of regional LV strains have implications for assessment of myocardial viability (Project 1) and evaluation of the potential substrate for angiogenesis (Project 2). Four other projects (Projects 3-6) require functional imaging of mice and rats for evaluation of a range of biological processes, including myocardial metabolism (Projects 3 & 6), vascular biology (Project 5), and hypoxic signaling (Project 4) in the heart. Purchase of the proposed system will permit extension of the current projects toward more clinically relevant issues for cardiovascular imaging. This shared instrumentation proposal represents an important step towards establishing a comprehensive experimental cardiovascular imaging center and a NIH supported training program.